The pace isn't slowing down much, either. EMarketer forecasts that e-commerce sales worldwide will rise more than 18%, to almost $1.3 trillion.

But more of the growth is coming from Asia. Sales in North America grew nearly 14% to $365 billion in 2012, still making it the leading world market. But growth will ease this year to 12.2% and Asia-Pacific revenues will overtake North America, growing more than 30% to $433 billion, to comprise more than a third of sales. The U.S. itself will remain the leader in e-commerce, though.

Not surprisingly, China leads the way, thanks to a growing Internet-connected middle class, more trust in online shopping, government campaigns to promote consumerism, improved infrastructure, and better product selection and services offered by online sellers and retailers, says eMarketer.